Synonyms for Rightfully:

adv.

all (adverb)
truly.
lawfully (adverb)
fairly, truly, legally, properly, equitably, impartially, justly, legitimately, honestly, fittingly.

adv

justly (adverb)
fittingly, impartially, legitimately, equitably.

n.

lawfully (noun)
legitimately, impartially, in all conscience, by rights, equitably, in reason, as is fitting, justly, legally, in equity, fairly, fair-and-square, dispassionately, on the level, properly, fittingly, by right, honestly, objectively.
rightfully (noun)
truly.

Other synonyms:

legally. honorably
justly.
Other relevant words:
dispassionately, in all conscience, honestly, by rights, by right, fittingly, in reason, properly, fairly, impartially, justly, legally, legitimately, equitably.

Usage examples for rightfully

  1. This was indeed unfortunate, yet it had its compensation, for each morning he anticipated an unhappy day, and when in the evening he looked back on nothing but pleasure and sunshine, he went to bed with a heart full of gratitude for the good which he had enjoyed but which did not rightfully belong to him. – The Complete Historical Romances of Georg Ebers by Georg Ebers
  2. It is true, as the will gives you to understand, said the lawyer, smiling in his dry way, and if I may be permitted to say so, Lady Garvington, never was money more rightfully inherited. – Red Money by Fergus Hume
  3. Her past was her own, and all he could rightfully claim was her future. – The Silver Horde by Rex Beach